Per my prior post on this topic, if the new 800 has an MFD <5m, built-in TC, superior IQ at 800 as compared to the 600II + 1.4XIII, IQ at 1120 = 600 + 1.4, and weighs less than 4 kg, I will purchase one even if it is priced a little north of the Nikon 800. These may be tough specs to meet, but the other series II superT's made improvements along these lines.